McCranie, James R. 2015. A checklist of the amphibians and reptiles of Honduras, with additions, comments on taxonomy, some recent taxonomic decisions, and areas of further studies needed. Zootaxa 3931 (3): 352–386 - get paper here

Savage, J.M. 2002. The Amphibians and Reptiles of Costa Rica: A Herpetofauna Between Two Continents, Between Two Seas. University of Chicago Press, 934 pp. [review in Copeia 2003 (1): 205]

Savage, Jay M.; Watling, James I. 2008. Not so rare snakes: a revision of the Geophis sieboldi group (Colubridae: Dipsadinae) in lower Central America and Colombia. Zoological Journal of the Linnean Society 153(3):561-599

Townsend, J. H. 2006. INVENTORY AND CONSERVATION ASSESSMENT OF THE HERPETOFAUNA OF THE SIERRA DE OMOA, HONDURAS, WITH A REVIEW OF THE Geophis (SQUAMATA: COLUBRIDAE) OF EASTERN NUCLEAR CENTRAL AMERICA. PhD thesis, University of Florida, 138 pp.